package com.dtstep.lighthouse.common.rpc.netty;
/*
 * Copyright (C) 2022-2025 XueLing.雪灵
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import com.dtstep.lighthouse.common.serializer.Serializer;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.util.List;

public class RpcDecoder extends ByteToMessageDecoder {

    private final Class<?> clazz;

    private final Serializer serializer;

    public RpcDecoder(Class<?> clazz,Serializer serializer){
        this.clazz = clazz;
        this.serializer = serializer;
    }

    @Override
    protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List<Object> list) throws Exception {
        if (byteBuf.readableBytes() < 4) {
            return;
        }
        byteBuf.markReaderIndex();
        int dataLength = byteBuf.readInt();
        if (byteBuf.readableBytes() < dataLength) {
            byteBuf.resetReaderIndex();
            return;
        }
        byte[] data = new byte[dataLength];
        byteBuf.readBytes(data);
        Object obj = serializer.deserialize(data,clazz);
        list.add(obj);
    }
}
